As known, the splicing operation of a new web to an almost exhausted web in use is normally carried out without stopping the feeding of the web in use to the labeling machine, but only by slowing its progress.
In particular, a double-sided adhesive sheet element is previously attached upon a head segment of the new web. Said segment of the new web is then made to adhere, thanks to the action of the double-sided adhesive, on a corresponding segment of the web in use so as to obtain alignment of the corresponding labels. Simultaneously to the splicing operation, the web in use is cut in the area located immediately upstream of the segments of the two webs united together by the double-sided adhesive sheet element. It is thus possible to restart the feeding of the labels to the labeling machine at normal speed.